Dark-type gym
Puzzle: When you step inside, the gym is pitch black. The only things you can see are your own character, the exit, and a single purple light. By walking toward the light, you initiate a trainer battle. After winning, a second light appears which also prompts a trainer battle when you get too close. Beating all of the trainers will reveal a path to the gym leader, however it is entirely possible to make your way through just stumbling in the dark.
Gym Battle theme:
http://www.youtube.com/watch?v=37fp9ebZ-4sQuotes:
Pre-battle: Made your way through the dark, huh? I hope you didn't hit your head too many times. Wouldn't want your battle prowess to be hampered by brain damage. Let's skip pleasantries and get straight to it.
Last pokemon: It all comes down to this. Can't lose steam now!
Last pokemon below half health: .........
Victorious in battle: Time to slip back into the shadows.
Defeated in battle: You are quite skilled.
Very well, you have earned this badge. I assume you're going to challenge the league? If so, you may want to take this TM. It will teach a Pokemon Nasty Plot, a devilishly useful move which increases Special Attack.
Rematch: Oh, it's you! I see... very well, I shall battle you, not as a Gym Leader but as a fellow trainer. This time I won't hold anything back!
Defeated: You have surpassed me in both skill and strength. You are a fine champion.
Pokemon: Sableye; Liepard; Tyranitar; Zoroark
Rematch: Zoroark; Cacturne; Houndoom; Sharpedo; Bisharp; Mandibuzz
>dat double Zoroark roll>dat Grass-Fire-Water core in the rematch>dat double Prankster in the initial battle 
